<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        div{/*块级元素特点：独占一行可以修改宽高*/
            width: 100px;
            height: 100px;
            border: 1px solid red;
        }
        span{ /* 行内元素特点：共占一行不能修改宽高*/
            border: 1px solid blue;
            width: 100px;
            height: 100px;
        }
        img{  /*行内块特点:共占一行，可以修改宽高*/
            width: 100px;
            height: 100px;
        }
        a{
            background-color: green;
            /*行内元素默认是不能修改宽高的，如果必修改则需要先将行内
            元素改成块级或行内块元素
             */
            display: block;
            width: 100px;
            height: 50px;
        }
    </style>
</head>
<body>
<a href="">超链接</a>
<a href="">超链接</a>
<div>div1</div>
<div>div2</div>
<div>div3</div>
<span>span1</span>
<span>span2</span>
<span>span3</span>
<img src="../b.jpg" alt="">
<img src="../b.jpg" alt="">
<img src="../b.jpg" alt="">
</body>
</html>